Centroid Community CNC Support Forum

Acorn Spindle Encoder Overview Video

https://youtu.be/Gk1T_9-7_4g

Just for clarification any 5 v line drive optical encoder will work. Correct?
I am looking at the Automation direct 1/4 inch Solid Shaft Line Driver (TRDA-2E Series).
https://www.automationdirect.com/adc/Sh ... A-2E2500VD

This is for my lathe spindle motor.
They have open collector and line drive. I assume open collector is not what I want. (edit: I just saw the open collector is 12v)

Clay

clay,
Hello.
http://www.automationdirect.com/pn/TRDA-2E2500VD
will work just fine with Acorn.

5 volt quadrature differential with A,A- B,B- Z,Z-

Out of curiosity, can you use an absolute encoder? Or only incremental?

ScotY wrote: ↑Sat Oct 21, 2017 12:57 am Out of curiosity, can you use an absolute encoder? Or only incremental?

INCREMENTAL, DIFFERENTIAL/LINE DRIVER OUTPUT ONLY, +5VDC input

I'm perplexed why guys keep fighting this....

Has anyone tried the modular CUI encoders from digikey? Iv been looking over the data sheet and I cannot see any reason they should not work. I am looking at the AMT113Q-V model specifically. Sorry if this has already been asked, i googled around but did not see it brought up. It is incremental, differential, quadrature line driver with 5VDC input and can be set up to 4096 ppr.

https://www.digikey.com/product-detail/ ... ND/4835229

http://www.cui.com/product/resource/amt11-v.pdf

WesM wrote: ↑Sat Nov 25, 2017 2:10 am Has anyone tried the modular CUI encoders from digikey? Iv been looking over the data sheet and I cannot see any reason they should not work. I am looking at the AMT113Q-V model specifically. Sorry if this has already been asked, i googled around but did not see it brought up. It is incremental, differential, quadrature line driver with 5VDC input and can be set up to 4096 ppr.

https://www.digikey.com/product-detail/ ... ND/4835229

http://www.cui.com/product/resource/amt11-v.pdf

Used as a spindle encoder?
I do t see any reason why they wouldn't work. I use them on servo motors on my Dyna DM4400 and they have been working fine with Logosol servo drives.
Marty

I'm using them with an OAK conversion of a Hardinge TFB for manual handwheel inputs. P/N is AMT112Q-V. Just be careful on max RPM or you'll exceed the bandwidth of the encoder. IIRC it's 4000rpm for resolutions above 768 ppr.

These are basic encoders - just the disc and housing. This means that you need to provide the shaft supported with bearings and mounting provisions for the housing to hold the housing and shaft relative to each other while allowing only rotation.

Cheers,

Tom

I am new to encoding terminology. I found the below passage helpful in understanding CPR and PPR. CPR most commonly stands for Counts per Revolution, and refers to the number of quadrature decoded states that exist between the two outputs A and B. With both outputs A and B switching between high and low, there exists 2 bits of information represented as 4 distinct states. The term quadrature decoding describes the method of using both outputs A and B together to count each state change. This results in 4 times the amount of counts that exist for each pulse or period. Therefore, the CPR of an encoder is the encoder’s PPR multiplied by 4.

Here's a good explanation of the differences between CPR, PPR, and LPR (w/pictures for the visual learners):

http://www.cui.com/blog/what-is-encoder-ppr-cpr-and-lpr

tl;dr:
PPR describes the number of high pulses an encoder will have on either of its square wave outputs A or B over a single revolution. Therefore, CPR(counts per rev) = 4*PPR(pulses per rev) = 4*LPR(lines per rev). Some manufacturers refer to CPR as cycles per rev in which their definition makes CPR = PPR which causes endless confusion.

Cheers,

Tom